If you want to create a webpage for a particular repo, this step is not required.
If you want to create a general homepage, create a project called <<my_github_username>>.github.io.
1. Set up GitHub pages on the repo you want
Under the repo go to Settings in the toolbar on the top.
Go the Pages section on the toolbar on the left.
Under Build and deployment: set Source to ‘Deploy from a branch’ and set Branch to the chosen branch. You can also set a folder to deploy from (e.g. ./docs) if the docs will not be contained in the root folder.
2. Create _config.yml
In the folder that was selected as the folder to deploy from, create a file called _config.yml.
Add in this line: remote_theme: just-the-docs/just-the-docs, as well as any other data you want to add (see the just-the-docs documentation for more details).
3. Add your pages as .md files
You can add information in YAML frontmatter e.g. layout, name, or permalink.